Anatomia foliar de Eugenia florida DC. (Myrtaceae)

Abstract

RESUMO:Foi feito o estudo anatômico da folha de Eugenia florida DC., espécie arbórea da família Myrtaceae, coletada no Campus da Fundação Oswaldo Cruz, Rio de Janeiro, RJ. A espécie apresenta importantes propriedades farmacológicas, incluindo-se atividade antiviral. O presente estudo teve como objetivo fornecer dados, revelados através da microscopia óptica e da microscopia eletrônica de varredura, que possam contribuir para o conhecimento da espécie e, conseqüentemente, para a segurança em sua identificação. Anatomicamente, a folha é hipostomática, com organização dorsiventral do mesofilo. Apresenta tricomas simples apenas sobre a nervura mediana da face adaxial. As células epidérmicas apresentam contorno sinuoso em vista frontal e cutícula estriada. O parênquima paliçádico destaca-se pela grande quantidade de cristais prismáticos de oxalato de cálcio. Em posição subepidérmica ocorrem cavidades secretoras de óleos essenciais, pouco numerosas, nas duas faces da lâmina foliar. As células epidérmicas situadas sobre as estruturas secretoras constituem característica de valor diagnóstico e são reconhecíveis pela célula de topo, que é reniforme, circundada pelas adjacentes, que apresentam disposição radiada. A comparação entre folhas de sol e de sombra revela que, nas primeiras, as estruturas secretoras são completamente diferenciadas, ao contrário das folhas de sombra, além de apresentarem maior concentração de compostos ergásticos.Unitermos: Eugenia florida, Myrtaceae, anatomia foliar, plantas medicinais, farmacobotânica.ABSTRACT: "Foliar anatomy of Eugenia florida DC. (Myrtaceae)". A study of the foliar anatomy of Eugenia florida DC., a tree of Myrtaceae family collected at Fundação Oswaldo Cruz, Rio de Janeiro, RJ, was accomplished. This species presents important pharmacological properties, including antiviral activity. The aim of this research was to furnish data, revealed by optical microscopy and scanning electronically microscopy, in order to contribute to the knowledge of the species and to its safe identification. Anatomically, the leaf is hipostomatic, with dorsiventral mesophyll. Simple unicellular hairs are present only on the adaxial side of the leaf in the midvein region. Anticlinal walls of epidermal cells are undulate and the cuticle is striate. Palisade parenchyma presents a large amount of prismatic oxalate crystals. In subepidermical position there are secretory cavities bearing ethereal oils. These structures occur in a low frequency and are scattered along the both sides of the foliar blade. The epidermal cells that overlap the secretory cavities form an important characteristic anatomical feature. They are recognizable by the top cell, which presents a kidney shape surrounded by cells in a radiate way. The comparison between sun and shade leaves shows a complete development of the secretory cavities and a higher concentration of ergastic compounds in the first ones.

Morpho-anatomy of the leaf and stem of Eugenia pyriformis

“…This type of stomata was also reported for E. florida (Donato & Morretes, 2009). Isobilateral mesophyll of E. copacabanensis Kiaersk.…”

“…In related species, this pattern has been found in E. umbelliflora O. Berg (guapê) (Medeiros, 2000) and E. florida DC. (Donato & Morretes, 2009).…”

Structural organization and phytochemical analysis of Pimenta dioica (L.) Merrill (Myrtaceae) leaves collected from Gois State, Brazil

“…The venation pattern (Figure 1d) is a pinned type camptodromus-brochidodromus in which the ribs diverge from the midrib at different angles and bend and arc (Figure 2a and b) before reaching the leaf margin. A similar venation pattern have also been recorded by Donato and Morretes (2009) for Eugenia florida DC, by Paula et al (2008) for P. pseudocaryophyllus (Gomes) LR Landrum and by Cardoso and Sajo (2006) for other species of Myrtaceae. The petiole is curved and varies from circular to biconvex, measures 0.5 to 0.7 cm in length, and its insertion and surface are marginal and striated, respectively.…”

Cloud forest trees with higher foliar water uptake capacity and anisohydric behavior are more vulnerable to drought and climate change

“…j). Collecting cells (Donato & Morretes, ; Donatini et al ., ) are the layer of mesophyll cells that connect the palisade parenchyma and the spongy mesophyll. The cytoplasmic extensions of collecting cells can be involved on the transport of solution deposited on the adaxial surface (Fig.…”